it was believed that he had rested the rear part of his palm on the left throttle. Due to this, as he decreased the reverse thrust of the right engine by pushing the lever forward, the left engine got caught with his palm and inadvertently moved forward, simultaneously, with the reverse thrust lever of the right engine. Normally, a significant amount of force is needed to move the throttle lever. In Flight 778, the throttle lever somehow managed to move quite easily even though Captain Shibanov had only applied small force, merely by resting his palm on the lever. It was discovered that the coupling that linked the throttle lever with the engine control had weakened. The throttle lever of the aircraft was equipped with a coupling. This would result in frictions and pilots would need to apply force to move it. To adjust the required forces, the tightness of the friction unit must be changed during a certain inspection. This inspection was carried out irregularly as it was only carried out whenever the pilots felt uncomfortable with the throttle. The logbook of the involved aircraft, F-OGYP, didn't even indicate that any inspection or correction regarding the friction forces had ever been conducted during its entire operational history. As per EASA, the problem of low friction forces on the linkage between the throttle control and the throttle lever was not considered as an airworthiness issue. Fleet inspection could only be carried out if there were continuous airworthiness concerns. F-OGYP, the involved aircraft, was considered to be old by investigators. As no inspection or correction had been carried out on the friction forces of the throttle control linkage, the coupling had weakened, which greatly reduced the forces needed to move the throttle by up to 400 g. By calculation, the forces were 3 times lower than the permissible amount. This explained why a relatively small force (e.g. resting palm) could move the throttle significantly forward. The accidental movement of the throttle lever, however, should have been noticed by the captain. The move itself was significantly large, reaching 60% on the thrust setting. According to investigators, another factor might have played a role in this matter. Simulations were conducted on an attempted landing in two different scenarios; landing on a smooth runway and a bumpy runway. The noticeability of the lever movement was significantly different between the two scenarios. Pilots were more